Corrugated vegetable-fiber board



Oct. 20, 1936. ML H MASON 2,058,334 l VCORRUGATED vnGETALE-FIBER BoARD AND THE PRocEss oF MAKINGI` `SAME omgaan4 Fileduuno 30,. 193s s` sheets-smet 1 w. H. MAsc'pN CORRUGATED VEGETABLE-.FIBER BOARD AND THE PROCESS OF MAKING SAME original' Filed Jue 30,1933 :s sheets-sheet 2 v O WW ww M .6 QM'. M A@ M n" WN N W Y u.. vm, N. Nw l, s. l l I l I .fi :i w u u. u W` N` N` NQ n A'rroRNEY Oct. 20, 1936. Y w, MASQN E "2,058,334

CORRUGATED VEGETABLEFIBER BOARD AND THE PROCESS' OF MAKING SAME Original Filed June 30, 19.33A 3 Sheets-Sheet 3` :18g I u lac ArroRNEY lgnliamfee oet. 2o, `1936- UNITED STATES am f CORRUGATED VEGETABLE-FIBER. 'BOARD AND4 THE PROCIISSA OFMAKING SAME William H. Mason, Laurel, Miss., assigner to Masonite Corporation, Laurel, Miss., a corporationoi Delaware f original puatron June salsas, sea-m No.

Divided and this application June My invention relates to the making of corrugated vegetable-fiber board, and has for its principal object the provision of a process forfconverting at sheets oi vegetabiehiiber'board into sheets with permanent corrugations therein. Anotherobject consists in the method of combining the corrugated board with flat boards iorthe making ofrigid, girder-iike products. Other objects are obvious or appear in connection with the folldwing description of preferred embodiments.

In the accompanying drawings forming a part of this specification:

Figure 1 is a part end view and part transversesectional view of one form of apparatus adapted `for carrying out my linvention;

Fig. 2 is a part plan view and part horizontal Vsectional view thereof, the sectional parts being :tEaiken substantially on the broken line 2-2 of Fig. 3 is a longitudinal sectional view-'taken Y substantially on the line 3-3 of Fig. 1;

Fig.-4 is a detail sectional view of-actuating mechanism including toggles and hydraulic cylinders;

gg Fig. 5 is a schematic view of pipe connections and valving for controlling the admission of iiuid to the hydraulic cylinders; Figs. 6, '1 and 8 are diagrammatical sectional views to illustrate stages in the pressing operaso tion.` Y

Fig. 9 is a perspective view of a piece oi' the Y- completed corrugated board; and

f' Fig. 10 is a cross sectional view of a built-up board, with stiffness and rigidity imparted thereto 35 by use of corrugated board, and withiacings of iiat sheet board.

The apparatus shown is described and claimed in copendingapplication Serial No.6'i8,401, filed June 30th, A1933, of which"l the preent application 40 is a division, and constitutes a simple form of hot pressing apparatus adapted for carrying out the `present invention, having a` framework I0 with cross beams I2 'for iixedly supporting the bed of the'- corrugating hot press, which in the form.

4.5 shown consists of a series of hollow cylinders or pipes I6 arranged in' parallel, and made of diameter and spacings dependent'on the corrugation height and transverse spacings desired for the board, and which` for a'boardof thickness` IB, and mounted to have forcible movement -toward and away from the bed pipes IB, as for ex ample, individually carried by means of several pairs of toggle arms -22, which arms -are pivoted at their respective ends to the pipes i8 and` 5 to thrust beams 24 of the machine frame I0. Actuation of the toggle arms and pipeA I8 carried thereby may be by link members 26, common to all the toggles attached to each length of pipe,

connecting rod 28, piston rod and piston 32 of l0 hydraulic cylinders 3l, which are rigidly supported, preferably in an end section 36 of the machine frame I0. f

The movement of pipes I8 is coniined to movement to and away from the pipes I6, and they are 15 restrained from lateral and endwise movement relative thereto. lSuch confinement may be secured by any suitable means, such as by prouviciing each pipe I8 with vertical studs or standards 38 that work in openings or passages `4I) 20 provided between guide bars 42, 44 fastened in place in the machine frame as indicated at 46, and also between guide blocks 48 connecting the guide bars `42, M. Such means or equivalent is shown at one endo! the movable pipes I8 only, 25 but may be duplicated at each-end oi the pipes,

if desired. The movable pipes I8 are further guided by -being received inthe recesses I8' between the xed pipes I6. y The lheating iluid. as steam, -that is supplied to $0 the press pipes I8, I8 may be supplied to the fixed press-bed pipes I6 by the rigid pipe I2, and to the movable pipes I8 by .the ilexible piping or hinged steam piping may be used, and preferably valved connections 56-58 are proso vided lfor permitting a return circulation of the heafting iluid, or same may be draw-oi! cocks for permitting escape of condensed steam.

In operation, the `ilat blank sheet 60 of vegetable-liber that is to be corrugated, (having been Y previously' wet and otherwise prepared for treat- `ment in manner hereinafter described), is inserted in place between the-bed pipes I8 and the ,movable pipes Il, the latter having been raised to permit such insertion.. The-central press cyl- ,A inder or pipe I Bd is tben'iorcibly depressed as by admission of oil or other iiuid under pressure at 62 to the central ione, 34a, of the hydraulic cylinders. 34, this being accomplished, for example, by opening supply' cock 02a. for this purpose, to- 50 gether with respectively closing and" opening the discharge cocks 64 and 66 for such cylinder. The supply cock 02a, as well as theotherlike supply cocks -for the other cylinders to be referred to.

' after beingl opened,. sre left open during the 55 pressing operation so that the pressure is maintained and followed up during drying.

The movable pipes or cylinders ISD-|811, adjacent toy the central pipe IBa and on each side thereof, are then forcibly depressed, as by supplying actuating uid to the hydraulic pressure cylinders by means of supply cock B2b, which, as shown in Fig. 5, communicates with the two corresponding cylinders 34b, 34h. Extra width of material needed to make the curved section is thus supplied from each side inwardly while the center of the sheet is rigidly clamped.

This operation progresses continuously, from the central portion of the sheet being pressed to-A ward each edge thereof, as by cock 62e being opened to supply actuating fluid to the cylinders 34e, 34e, thereby depressing press pipes I8c, I8c, and so on seriatim, press cylinder 34d, 34d being next operated so that pipes lad, I8d are depressed, and finally the outer pair 34e, 34e.

Figure 6 shows the central press pipe or cylinder |8a depressed. Figure 'l shows same remaining depressed and with the adjacent press cylinders lsb, |8b depressed, and Figure il shows how this progressive pressing operation proceeds, the next adjacent pair of press pipes I8c, l8c being also depressed. It will be understood that seriesoperated valves, capable of rapid automatic actuation, can be used instead ofthe manual valves, which are illustrated and described for affording a simple disclosure and clear understanding of the invention and how it may be carried out.

The open character of the press platens consisting of the bed pipe I6 and movable press pipes I8 favors the rapid drying of the initially Wet blank being operatedon, vthe steam formed escaping lfreely through the board without the restraint that would be encountered with solid continuous platens. `When the corrugated board is dry, the corrugated sheet, which is of sub'v stantially the original length, but of somewhat reduced overall width, is released by raising all the movable pipes I8 together, as by means of opening cocks to a supply inlet, 10, which may be common to all the cylinders 34 of the series, outlet .valves 66 having been closed, outlet valves 64 opened, and sup'ply valves 62 closed. This elelvates the movable press cylinders or pipes I8,

and the nished board can be removed.

'Ihe steps as above described can be followed with materials of various kinds having suicient plasticity when wet and becoming rigid upon being dried out.

The preferred blanks to be used, however, are at sheets of the hard, stiff, dense and strong composition board of my Patent No. 1,663,505,

made from the wood or woody constituents of fibrous vegetable material, such as so-called soft wood or hard wood of trees, or of vegetable growths of various kinds, including bamboo, cane and other wood-forming grasses, and the like, reduced to fiber in a manner to retain sufficient of the non-cellulose constituents of the fiber to make it self-bonding; vand a wet-lapof the fiber, preferably having about 2%i of waterproofing petrolatum size incorporated, dried under heat and consolidating pressure, followed up as shrinkage proceeds, and with a wirescreen in place between the wet-lap and a'press platen.

posed to the elements, as when used for roofing, such sheets, prior to being corrugated, are preferably given treatment, wholly or in part, as follows: The ilat sheets to be corrugated are tempered, as by incorporating with the fiber or impregnatng the pressed sheet with about 2% to 5% by weight of siccative oil,.as tung oil or linseed oil or mixtures thereof, and baked, as for a period of about 5 to 6 hours at about 300 F. This treatment gives a notable increase in the strength of t'ne board when wet as well as when dry, and materially reduces the water absorption.

Further siccative oil is applied to the surface, preferably the wire-mesh surface of the sheet that is'later to be corrugated, and the sheet heated for a short time, say about an hour, so

stituting the press platens at 70# per square inch, sheets 1/8" thick are dried in about 20 minutes, the openwork construction of the spaced pipes permitting ready escape of the moisture.

'I'he corrugated board that comes from the corrugating press is preferably now retempered as by submerging in a bath of siccative oil until about 2` to 5% by Weight of oil has been absorbed, and removing and baking for about 5-6 hours at a temperature in the neighborhood .of 300? F. Preferably, not over 5% of siccative oil is used in any tempering step or operation, since the strength curve falls off upon use of more oil than this,v as for example, use of enough oil to produce saturation, and the baking period has to be excessively prolonged. With sheets treated in the manner described, the fibers are apparently locked in the corrugated position, for the corrugations are retained even under severe conditions of alternate wetting and drying out in use.

'Ihe corrugated sheet can be used in various Ways similarly to sheets of corrugated iron, with the advantage that'it does not readily transmit heat, needs no coating, and is fee from rust and from corrosion, as when used in chemical plant construction, or exposed to salt air near the sea coast, and the like; by suitably modifying the corrugation spacing and height, the corrugated sheets can be cut into rooting tiles and and partitions of buildings, table tops and otherplaces where a stiff panel is required, by planing the apices of the corrugations of! flat to give -a broad gluing surface Vas indicated at Il, Fig. 10, and gluing dat surtaceplates 02, 8l ofvege- ,table-fiber board, tempered or untempered.

thereto with waterproof glue or equivalent cementitious material, indicated at II.

I claim: h

1. Process of making conugated hard vegetable-fiber board which comprises hot pressing corrugations into a, wet sheet thereof progressively along openly spaced lines from the median line toward both edges thereof, and continuing the application of heat and pressure untilsubstantially completely dry. v

2. Process of making hard, corrugated board of vegetable-iiber which comprises forming vegetable fiber containing. suiiicient non-cellulose material to be'self-bonding into a hard board by simultaneous application of consolidating heat and pressure, tempering same by incorporating about 2 to 5% of siccative oil `material and baking ata temperature in the neighborhood of 300 F. for a period of several hours, wetting the tempered board, and drying it from wet state in a heated corrugating press. andre-tempering in substantially the same way as before.

3. Process of making hard, corrugated board of vegetable-ber containing suiiicient noncellulose constituents to be self-bonding comprising forming same' into a hard board by simultaneous application of consolidating heat and pressure until dry, wetting the board so produced, hot pressing the wet sheet progressively along openly spaced lines at each side and continuing the application of heat and pressure until substantially completely dry.

4. Process according to the preceding claim together with tempering the corrugated board by incorporating about 2 to 5% of siccative oil and baking at a temperature in the neighborhood of 300 F. for a period oi several hours.

5. Stii girder-like products comprising corrugated, hard vegetable-ilber board of specific gravity one or more than one and having at surfaces of material width at the apices of the corrugations, andv similar but flat surfacing boards cemented -to the corrugated board along the flattened parts of the lines of corrugation.

v6. Process of making corrugated hard vegetable-fiber boards which comprises applying heat and pressure to a wet blank of such material on one side along openly spaced apart lines and applying heat and vpressure to the other side of the blank -along openly. spaced apart lines staggered in relation to the first set, and retaining the blank under pressure until substantially dried.-l

7. Process of making corrugated hard vegetable-fiber boards which comprises applying heat and pressure to a wet blank of such material on one side along openly spaced apart lines and applying heat and pressure to the other side of the blank along openly spaced apart lines staggered in relation to the rst set.

WILIJAM HQMAsoN. 

